Quote:
Originally Posted by x622
My experience with subaru engines tells me that this is likely because of the absolutely garbage flow characteristics of the heads. I look at all the EJ257 builds I've been apart of over the past decade and change and one of the huge issues with Subaru designs is the heads.
You have to really WORK to get past 300 cfm a runner, and there isn't a ton of material to remove before you hit a water jacket or something else in the heads. Oversized valves (which affect the velocity and gas reversion), extremely aggressive camshaft profiles (read about them cracking) combined with very aggressive springs are par for the course just to get those hunks of garbage to 300cfm, and just like you'd expect you're really shifting the curve to the right side of the graph which means that the bottom is only worse. Compare and contrast this to a K F or practically any other engine from any other manufacturer, there's a reason why they are more responsive to playing with forced induction.
Next as you mention, they just bored out the block, it was an 86 x 86 setup (1998.23cc) and now it's a 94mm bore.
Here's a pic of what 86mm pistons look like in a FA20 block. What do you think a FA24 looks like with 4mm less sleeve on all sides? I bet they're gonna have a ton of fun trying to get these POS engines not to pop head gaskets just like the EJ even with o-rings and a closed deck and all the other tricks thrown at it.
TL;DR
Subaru is dead to me. I see threads like this, and I don't know why I click them but I do and it just fills me with sadness and anger. Another Japanese manufacturer that just shit on the enthusiasts. |
Not a very robust looking open deck block. Looks like it won't be able to withstand a lot of boost and abuse.